What is the gram reaction for your unknown bacteria?

If you have an unknown bacteria and you want to identify it, you’ll typically perform a gram stain and then observe the colony appearance and the individual features. At that point, you can say you have, for example, a gram-negative, aerobic streptobacilli.

How do laboratories identify unknown bacteria?

Identification of unknown bacteria is an integral module in most introductory Microbiology laboratory courses. This laboratory activity typically involves identifying bacteria based on Gram staining for morphology and gram reaction followed by studying their biochemical characteristics.

What are the characteristics of Gram negative bacteria?

One of the several unique characteristics of gram-negative bacteria is the structure of the bacterial outer membrane. The outer leaflet of this membrane comprises a complex lipopolysaccharide (LPS) whose lipid portion acts as an endotoxin.

Why Gram negative bacteria more resistant to antibiotics?

The problem with gram-negative bacteria. This means that if a gram-negative bacterium either undergoes a genetic change (mutation) or acquires genetic material that confers resistance to an antibiotic, the bacterium may later share its DNA with another strain of bacteria and the second strain can become resistant as well.

Which antibiotics treat Gram negative bacteria?

There are several antibiotics for treating gram negative bacterial infections, including levofloxacin, moxifloxacin, ampicillin, chloramphenicol, streptomycin, and nalidixic acid.

What are Gram negative organisms?

The Gram-negative bacteria include most of the bacteria normally found in the gastrointestinal tract that can be responsible for disease as well as gonococci (venereal disease) and meningococci (bacterial meningitis). The organisms responsible for cholera and bubonic plague are Gram-negative. The Danish bacteriologist J.M.C.